1) Is there any physical difference between the CM Display and i1 Display Pro? Is the '5X slower' measuring cycle a limitation of the EyeOne software or inherent to the hardware? Will both devices perform at the same speed with third-party CMS software?
It's a limitation based on the software driving it, at least when you look at the differences between the same hardware with respect to ColorMunki Display and i1Display-Pro or whatever these products are now called. Does it matter that it takes say a few minutes longer? The old Artisan took 12 minutes if memory serves me.
The bigger differences is the lame software the Munki provides. You're getting the same quality colorimeter. You're getting slower measuring times which isn't a big deal really. The big deal is you are stuck with settings that may not provide a visual match to say a print. So you're paying less for the same quality hardware only to get crippled software and worse, I don't think you can upgrade just the software.